The present invention relates to method and apparatus for processing hose material in which hose material is delivered to a fitting arm which automatically fits the hose material to a bite member in a crotch sewing machine for panty hose in a state that the welt portion of the hose material is opened.
In manufacturing panty hose, two cylindrical pieces of hose material are set with their welt portions aligned right and left, in which state their thigh portions which form the panty part are sewn by a crotch sewing machine, and then the tip portions of this hose material pieces are sewn by a toe sewing machine. Thus, a pair of panty hose can be obtained.
The piece of panty hose finished with the sewing work is further subjected to various working processes such as dyeing, set finishing and packaging, thus being formed into a product.
As described above, the panty hose has been produced through the two processes of crotch sewing and toe sewing. As sewing machines for performing both processes, the automatic crotch sewing machine (U.S. Pat. No. 3,777,681) and the automatic toe sewing machine (U.S. Pat. No. 4,133,280) that the present inventor previously developed have been widely used.
Also, for the production of panty hose using these two sewing machines, there have been proposed, by U.S. Pat. No. 5,040,475 and U.S. Pat. No. 5,165,355, a processing apparatus which can feed suction-conveyed hose material for the welt-portion opening mechanism which makes the welt portion of the hose material opened by suction air flow in a fixed position, and which allows the panty hose sewing process to be completely automatized by connecting the welt-portion opening mechanism to the fitting arm of the crotch sewing machine.
In these processing apparatuses, pickup means for lifting the hose material to just above a storage container that randomly stores the hose material therein, and the lifted hose material is transported by transport pipe with air turbulence. During this transport, it is detected by sensor means whether the front end portion of the hose material is a welt portion or a toe, depending on a quantitative difference between welt portion and toe. After this, the hose material is posture-controlled and delivered to the welt-portion opening mechanism.
In this connection, the pickup means in the conventional processing apparatus as described above would be such that, in picking up the hose material, two pickup means are used and operated to go up and down in two stages, where the hose material is picked up from the storage container at the first stage, and re-picked up at the free end portion of the picked-up material at the second stage, so that the picked-up material is shaken off into one material piece so as not to pick up any plurality of material. At the second stage, a free end of this picked-up material is re-picked up and shaken off into open piece. However, this would result in much time consumption for the pickup work of the hose material so that the whole apparatus could not be operated efficiently. Moreover, this would result in a deterioration of the crotch sewing machine or toe sewing machine.
Also, the hose material picked up at the first stage is not always picked up under the same conditions so that they are picked up in an unstable state such as a folded-in-two state or materials entangled state. Therefore, at the second-stage re-picking state, the material is not necessarily shaken off into open piece, which causes a problem of deficient reliability.
Further, the conventional welt-portion opening mechanism as described above is not to completely unfold the welt portion at the opening end of the pipe but only to open it into, for example, a bugle shape, thus resulting in an unstable opening stat. As a result, the opening portion, even if opened, may shrink when the fitting arm is inserted into the opening portion, so that the delivery to the fitting arm cannot be performed smoothly, which would make an obstacle to the delivery work. In particular because this delivery work is the final process of the processing apparatus, it may be a critical defect to the processing apparatus.